/* Dartic landing page
   Editorial, tool-like design: paper + ink, one accent, 1px rules, mono labels. */

@font-face {
  font-family: "Space Grotesk";
  src: url("assets/fonts/SpaceGrotesk-Regular.ttf") format("truetype");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "Space Grotesk";
  src: url("assets/fonts/SpaceGrotesk-Medium.ttf") format("truetype");
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: "Space Grotesk";
  src: url("assets/fonts/SpaceGrotesk-SemiBold.ttf") format("truetype");
  font-weight: 600;
  font-display: swap;
}
@font-face {
  font-family: "Space Grotesk";
  src: url("assets/fonts/SpaceGrotesk-Bold.ttf") format("truetype");
  font-weight: 700;
  font-display: swap;
}

/* ── Tokens ─────────────────────────────────── */

:root {
  --bg: #f4f3ee;
  --surface: #fbfaf7;
  --surface-2: #ecebe4;
  --ink: #111214;
  --ink-2: #3b3e44;
  --muted: #6f7279;
  --line: #dcdad2;
  --line-strong: #c4c2b8;
  --accent: #0b63e5;
  --on-accent: #ffffff;
  --good: #1f8a4c;
  --bad: #c8372d;
  --code-bg: #15171b;
  --code-line: #262930;
  --code-ink: #d8dee9;

  --display: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;

  --gutter: clamp(16px, 4vw, 40px);
  --max: 1200px;
  --radius: 10px;

  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0c0d0f;
    --surface: #131417;
    --surface-2: #1a1c20;
    --ink: #edece7;
    --ink-2: #c3c3be;
    --muted: #8c8f95;
    --line: #24262b;
    --line-strong: #34373e;
    --accent: #5b9dff;
    --on-accent: #08111f;
    --good: #45c27a;
    --bad: #ff6b5e;
    --code-bg: #101114;
    --code-line: #22252b;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #0c0d0f;
  --surface: #131417;
  --surface-2: #1a1c20;
  --ink: #edece7;
  --ink-2: #c3c3be;
  --muted: #8c8f95;
  --line: #24262b;
  --line-strong: #34373e;
  --accent: #5b9dff;
  --on-accent: #08111f;
  --good: #45c27a;
  --bad: #ff6b5e;
  --code-bg: #101114;
  --code-line: #22252b;
  color-scheme: dark;
}

/* ── Base ───────────────────────────────────── */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1,
h2,
h3,
h4 {
  font-family: var(--display);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 0;
  text-wrap: balance;
}

p {
  margin: 0;
}

a {
  color: inherit;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

code,
pre,
kbd {
  font-family: var(--mono);
}

button {
  font: inherit;
  color: inherit;
}

[hidden] {
  display: none !important;
}

::selection {
  background: var(--accent);
  color: var(--on-accent);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 100;
  padding: 8px 14px;
  background: var(--ink);
  color: var(--bg);
  border-radius: 6px;
  text-decoration: none;
}
.skip-link:focus {
  top: 12px;
}

.container {
  width: 100%;
  max-width: calc(var(--max) + var(--gutter) * 2);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* Mono label used for section numbers and kickers */
.label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}
.label b {
  color: var(--ink);
  font-weight: 500;
}

/* ── Buttons ────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  height: 46px;
  padding: 0 20px;
  border-radius: 8px;
  border: 1px solid transparent;
  font-family: var(--display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease, transform 0.15s ease;
}
.btn:active {
  transform: translateY(1px);
}
.btn svg {
  width: 18px;
  height: 18px;
  flex: none;
}

.btn-ink {
  background: var(--ink);
  color: var(--bg);
}
.btn-ink:hover {
  background: var(--accent);
  color: var(--on-accent);
}

.btn-line {
  border-color: var(--line-strong);
  color: var(--ink);
}
.btn-line:hover {
  border-color: var(--ink);
}

.btn-sm {
  height: 38px;
  padding: 0 14px;
  font-size: 14px;
}

.icon-btn {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: transparent;
  cursor: pointer;
  transition: border-color 0.15s ease;
}
.icon-btn:hover {
  border-color: var(--ink);
}
.icon-btn svg {
  width: 18px;
  height: 18px;
}

.theme-toggle .sun {
  display: none;
}
:root[data-theme="dark"] .theme-toggle .sun {
  display: block;
}
:root[data-theme="dark"] .theme-toggle .moon {
  display: none;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-toggle .sun {
    display: block;
  }
  :root:not([data-theme="light"]) .theme-toggle .moon {
    display: none;
  }
}

/* ── Header ─────────────────────────────────── */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(14px);
  -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}
.site-header.scrolled {
  border-bottom-color: var(--line);
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
  height: 64px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--display);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -0.03em;
  text-decoration: none;
  color: var(--ink);
}
.brand img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.nav-links {
  display: flex;
  gap: 4px;
  list-style: none;
  margin: 0 auto 0 0;
  padding: 0;
}
.nav-links a {
  display: block;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 14.5px;
  color: var(--ink-2);
  text-decoration: none;
  transition: color 0.15s ease, background-color 0.15s ease;
}
.nav-links .nav-gh {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}
.gh-stars {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-left: 2px;
  padding: 2px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.gh-stars svg {
  color: #e3b341;
}
.gh-stars b {
  font-weight: 500;
}
.nav-links a:hover {
  color: var(--ink);
  background: var(--surface-2);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.menu-toggle {
  display: none;
}

/* ── Hero ───────────────────────────────────── */

.hero {
  padding: clamp(40px, 7vw, 88px) 0 0;
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: clamp(32px, 5vw, 72px);
  align-items: end;
}

.hero-copy {
  padding-bottom: clamp(40px, 6vw, 88px);
}

.hero h1 {
  margin: 22px 0 26px;
  font-size: clamp(48px, 8.2vw, 108px);
  font-weight: 600;
  line-height: 0.94;
  letter-spacing: -0.055em;
}
.hero h1 em {
  font-style: normal;
  color: var(--accent);
}
.hero h1 .cursor {
  display: inline-block;
  width: 0.07em;
  height: 0.78em;
  margin-left: 0.05em;
  background: var(--accent);
  vertical-align: -0.04em;
  animation: blink 1.1s steps(1) infinite;
}
@keyframes blink {
  50% {
    opacity: 0;
  }
}

.hero-lead {
  max-width: 34em;
  font-size: clamp(17px, 1.5vw, 19px);
  line-height: 1.55;
  color: var(--ink-2);
}
.hero-lead code {
  font-size: 0.88em;
  padding: 1px 5px;
  border-radius: 4px;
  background: var(--surface-2);
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 32px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
}
.hero-meta b {
  color: var(--ink);
  font-weight: 500;
}

/* Real app screenshots, cropped at the fold like a device rising from the page */
.hero-shots {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: flex-end;
  height: 100%;
  min-height: 420px;
}

.shot {
  position: relative;
  width: min(300px, 46vw);
  aspect-ratio: 1206 / 2200;
  border-radius: 36px 36px 0 0;
  border: 1px solid var(--line-strong);
  border-bottom: 0;
  background: var(--surface);
  padding: 9px 9px 0;
  overflow: hidden;
}
.shot img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  border-radius: 28px 28px 0 0;
}
.hero-shots .shot.front {
  z-index: 1;
  transform: translateX(-18%);
  box-shadow: 0 40px 80px -40px rgba(0, 0, 0, 0.45);
}
.hero-shots .shot.back {
  position: absolute;
  right: 0;
  bottom: 0;
  width: min(250px, 38vw);
  aspect-ratio: 1206 / 2000;
}

/* ── Topic ticker ───────────────────────────── */

.ticker {
  border-bottom: 1px solid var(--line);
  overflow: hidden;
  white-space: nowrap;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
  mask-image: linear-gradient(90deg, transparent, #000 8%, #000 92%, transparent);
}
.ticker-track {
  display: inline-flex;
  padding: 16px 0;
  animation: ticker 70s linear infinite;
}
.ticker-track span::after {
  content: "/";
  margin: 0 22px;
  color: var(--line-strong);
}
@keyframes ticker {
  to {
    transform: translateX(-50%);
  }
}

/* ── Sections ───────────────────────────────── */

.section {
  padding: clamp(72px, 10vw, 128px) 0;
  border-bottom: 1px solid var(--line);
}

.section h2 {
  margin-top: 18px;
  font-size: clamp(36px, 5vw, 64px);
  letter-spacing: -0.045em;
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 24px 64px;
  align-items: end;
  margin-bottom: clamp(40px, 5vw, 64px);
}
.section-head p {
  max-width: 30em;
  font-size: 17px;
  color: var(--ink-2);
}

/* ── Bento ──────────────────────────────────── */

.bento {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.cell {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: clamp(22px, 2.6vw, 34px);
  background: var(--surface);
  min-width: 0;
}
.cell h3 {
  font-size: clamp(22px, 2.2vw, 28px);
  letter-spacing: -0.035em;
}
.cell p {
  color: var(--ink-2);
  max-width: 34em;
}

.c-7 {
  grid-column: span 7;
}
.c-5 {
  grid-column: span 5;
}
.c-12 {
  grid-column: span 12;
}

/* Test-run fragment for algorithm practice */
.tests {
  margin-top: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-family: var(--mono);
  font-size: 13px;
  overflow: hidden;
}
.tests div {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
  color: var(--ink-2);
}
.tests div:last-child {
  border-bottom: 0;
  background: var(--surface-2);
  color: var(--ink);
}
.tests .ok {
  color: var(--good);
}
.tests .ms {
  margin-left: auto;
  color: var(--muted);
}

/* Paths table */
.paths {
  margin-top: auto;
  border-top: 1px solid var(--line);
}
.path {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr) auto;
  gap: 16px;
  align-items: baseline;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}
.path:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}
.path .n {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
}
.path h4 {
  font-size: 19px;
  letter-spacing: -0.02em;
}
.path p {
  margin-top: 4px;
  font-size: 14.5px;
}
.path .meta {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  text-align: right;
  white-space: nowrap;
}

/* Full-width paths cell: three columns on wide screens */
@media (min-width: 1025px) {
  .c-12 .paths {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 32px;
  }
  .c-12 .path {
    grid-template-columns: 32px minmax(0, 1fr);
    border-bottom: 0;
    padding-bottom: 0;
  }
  .c-12 .path .meta {
    grid-column: 2;
    text-align: left;
    margin-top: 6px;
  }
}

/* Inline screenshot that bleeds off the bottom of a cell */
.cell.has-shot {
  padding-bottom: 0;
  overflow: hidden;
}
.cell-shot {
  margin: 12px auto 0;
  width: min(260px, 78%);
  aspect-ratio: 1206 / 1350;
  border: 1px solid var(--line-strong);
  border-bottom: 0;
  border-radius: 30px 30px 0 0;
  padding: 7px 7px 0;
  background: var(--bg);
  overflow: hidden;
}
.cell-shot img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  border-radius: 23px 23px 0 0;
}

/* ── Code window ────────────────────────────── */

.code-window {
  min-width: 0;
  margin-top: auto;
  border-radius: 8px;
  overflow: hidden;
  background: var(--code-bg);
  color: var(--code-ink);
  font-family: var(--mono);
  font-size: 13.5px;
  border: 1px solid var(--code-line);
}
.code-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  height: 44px;
  padding: 0 8px 0 14px;
  border-bottom: 1px solid var(--code-line);
  color: #8b93a1;
  font-size: 12.5px;
}
.code-bar .file {
  color: #d8dee9;
}
.run-btn {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  height: 30px;
  padding: 0 12px;
  border: 1px solid #343944;
  border-radius: 6px;
  background: #1d2026;
  color: #e5e9f0;
  font-family: var(--mono);
  font-size: 12.5px;
  cursor: pointer;
  transition: background-color 0.15s ease, border-color 0.15s ease;
}
.run-btn:hover:not(:disabled) {
  background: #262a32;
  border-color: #4a5060;
}
.run-btn:disabled {
  cursor: progress;
  opacity: 0.7;
}

.code-window pre {
  margin: 0;
  padding: 16px 0;
  overflow-x: auto;
  line-height: 1.7;
  counter-reset: ln;
}
.code-window pre .ln {
  display: block;
  padding-right: 18px;
  white-space: pre;
}
.code-window pre .ln::before {
  counter-increment: ln;
  content: counter(ln);
  display: inline-block;
  width: 44px;
  padding-right: 16px;
  text-align: right;
  color: #4c5361;
}

.code-output {
  border-top: 1px solid var(--code-line);
  padding: 12px 18px 16px;
  min-height: 112px;
}
.code-output .label {
  color: #6b7383;
  font-size: 11px;
}
.code-output .out {
  display: block;
  margin-top: 8px;
  white-space: pre-wrap;
  color: #a3be8c;
}
.code-output .out.idle {
  color: #6b7383;
}

/* Nord tokens, matching the in-app editor theme */
.tok-k {
  color: #81a1c1;
}
.tok-t {
  color: #8fbcbb;
}
.tok-f {
  color: #88c0d0;
}
.tok-s {
  color: #a3be8c;
}
.tok-n {
  color: #b48ead;
}
.tok-c {
  color: #616e88;
  font-style: italic;
}

/* ── Curriculum ─────────────────────────────── */

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 40px clamp(32px, 6vw, 96px);
  align-items: start;
}
.split-aside p {
  margin-top: 20px;
  color: var(--ink-2);
  max-width: 26em;
}
.sticky {
  position: sticky;
  top: 96px;
}

.seg {
  display: inline-flex;
  margin-top: 28px;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: var(--surface);
}
.tab {
  height: 36px;
  padding: 0 14px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-family: var(--display);
  font-size: 14.5px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
}
.tab[aria-selected="true"] {
  background: var(--ink);
  color: var(--bg);
}
.tab:not([aria-selected="true"]):hover {
  color: var(--ink);
}

.totals {
  display: flex;
  gap: 32px;
  margin-top: 32px;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
}
.totals b {
  display: block;
  font-family: var(--display);
  font-size: 34px;
  font-weight: 600;
  letter-spacing: -0.04em;
  color: var(--ink);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}

.toc {
  border-top: 1px solid var(--ink);
}

.module {
  border-bottom: 1px solid var(--line);
}
.module summary {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) auto 14px;
  gap: 16px;
  align-items: baseline;
  padding: 22px 0;
  cursor: pointer;
  list-style: none;
}
.module summary::-webkit-details-marker {
  display: none;
}
.module .num {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
}
.module h3 {
  font-size: clamp(20px, 2vw, 24px);
  letter-spacing: -0.03em;
  transition: color 0.15s ease;
}
.module summary:hover h3 {
  color: var(--accent);
}
.module .desc {
  display: block;
  margin-top: 4px;
  font-size: 14.5px;
  color: var(--muted);
}
.module .count {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  white-space: nowrap;
}
.module .chev {
  position: relative;
  width: 12px;
  height: 12px;
  align-self: center;
}
.module .chev::before,
.module .chev::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1.5px;
  background: var(--ink);
  transition: transform 0.2s ease;
}
.module .chev::after {
  transform: rotate(90deg);
}
.module[open] .chev::after {
  transform: rotate(0);
}

.module ol {
  columns: 2;
  column-gap: 32px;
  margin: 0;
  padding: 0 0 26px 60px;
  list-style: none;
  counter-reset: lesson;
}
.module li {
  break-inside: avoid;
  padding: 5px 0;
  font-size: 15px;
  color: var(--ink-2);
  counter-increment: lesson;
}
.module li::before {
  content: counter(lesson, decimal-leading-zero);
  display: inline-block;
  width: 32px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
}

/* ── Quiz ───────────────────────────────────── */

.quiz-score {
  display: flex;
  gap: 6px;
  margin-top: 32px;
}
.quiz-score span {
  width: 40px;
  height: 6px;
  border-radius: 3px;
  background: var(--line);
  transition: background-color 0.2s ease;
}
.quiz-score span.current {
  background: var(--ink);
}
.quiz-score span.good {
  background: var(--good);
}
.quiz-score span.bad {
  background: var(--bad);
}

.quiz-card {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: clamp(20px, 3vw, 32px);
}
.quiz-top {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.quiz-q {
  margin-top: 18px;
  font-family: var(--display);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.02em;
}
#quiz-code {
  margin: 16px 0 0;
  padding: 16px 18px;
  border-radius: 8px;
  background: var(--code-bg);
  color: var(--code-ink);
  font-size: 13.5px;
  line-height: 1.65;
  overflow-x: auto;
}
.quiz-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 16px;
}
.quiz-option {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 52px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg);
  font-family: var(--mono);
  font-size: 14.5px;
  text-align: left;
  cursor: pointer;
  transition: border-color 0.15s ease, background-color 0.15s ease;
}
.quiz-option:hover:not(:disabled) {
  border-color: var(--ink);
}
.quiz-option:disabled {
  cursor: default;
}
.quiz-option .key {
  display: inline-grid;
  place-items: center;
  width: 24px;
  height: 24px;
  flex: none;
  border: 1px solid var(--line-strong);
  border-radius: 5px;
  font-size: 12px;
  color: var(--muted);
}
.quiz-option.correct {
  border-color: var(--good);
  background: color-mix(in srgb, var(--good) 10%, var(--bg));
}
.quiz-option.correct .key {
  border-color: var(--good);
  background: var(--good);
  color: #fff;
}
.quiz-option.wrong {
  border-color: var(--bad);
  background: color-mix(in srgb, var(--bad) 9%, var(--bg));
}
.quiz-option.wrong .key {
  border-color: var(--bad);
  background: var(--bad);
  color: #fff;
}
.quiz-feedback {
  margin-top: 16px;
  font-size: 15px;
  color: var(--ink-2);
}
.quiz-feedback:empty {
  display: none;
}
.quiz-feedback strong {
  color: var(--ink);
}
.quiz-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
}

/* ── FAQ ────────────────────────────────────── */

.faq {
  border-top: 1px solid var(--ink);
}
.faq details {
  border-bottom: 1px solid var(--line);
}
.faq summary {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 22px 0;
  font-family: var(--display);
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.02em;
  cursor: pointer;
  list-style: none;
}
.faq summary::-webkit-details-marker {
  display: none;
}
.faq summary::after {
  content: "+";
  font-family: var(--mono);
  font-weight: 400;
  color: var(--muted);
  transition: transform 0.2s ease;
}
.faq details[open] summary::after {
  transform: rotate(45deg);
}
.faq details p {
  padding: 0 48px 24px 0;
  color: var(--ink-2);
  max-width: 40em;
}

/* ── CTA ────────────────────────────────────── */

.cta {
  padding: clamp(80px, 12vw, 160px) 0;
  border-bottom: 1px solid var(--line);
}
.cta-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.65fr);
  gap: 40px;
  align-items: end;
}
.cta h2 {
  font-size: clamp(44px, 7.2vw, 100px);
  line-height: 0.95;
  letter-spacing: -0.055em;
}
.cta-kicker {
  display: block;
  margin-bottom: 22px;
  font-weight: 400;
  letter-spacing: 0;
  line-height: 1.4;
  font-family: var(--mono);
  font-size: clamp(14px, 1.3vw, 16px);
  color: var(--accent);
}
.cta-side p {
  color: var(--ink-2);
  max-width: 24em;
}

.store-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}
.store-btn {
  height: 54px;
  padding: 0 18px;
  background: var(--ink);
  color: var(--bg);
  border-radius: 10px;
}
.store-btn span {
  display: grid;
  line-height: 1.15;
  text-align: left;
}
.store-btn small {
  font-family: var(--sans);
  font-size: 10.5px;
  font-weight: 500;
  opacity: 0.75;
}
.store-btn strong {
  font-size: 17px;
  letter-spacing: -0.02em;
}
.store-btn svg {
  width: 22px;
  height: 22px;
}
.store-btn:hover {
  background: var(--accent);
  color: var(--on-accent);
}
.store-btn[aria-disabled="true"] {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-strong);
  cursor: default;
}
.cta-note {
  margin-top: 16px;
  font-size: 14px;
  color: var(--muted);
}
.cta-note:empty {
  display: none;
}

/* ── Footer ─────────────────────────────────── */

.site-footer {
  padding: 56px 0 40px;
  font-size: 14.5px;
  color: var(--muted);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(3, 1fr);
  gap: 32px;
}
.footer-grid p {
  margin-top: 14px;
  max-width: 300px;
}
.footer-grid h4 {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink);
  margin-bottom: 14px;
}
.footer-grid ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.footer-grid a {
  text-decoration: none;
}
.footer-grid a:hover {
  color: var(--ink);
}
.footer-bottom {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 12.5px;
}
.footer-bottom a {
  text-decoration: none;
}
.footer-bottom a:hover {
  color: var(--ink);
}

/* ── Reveal ─────────────────────────────────── */

.js .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1);
}
.js .reveal.visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .js .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .ticker-track,
  .hero h1 .cursor {
    animation: none;
  }
}

/* ── Responsive ─────────────────────────────── */

@media (max-width: 1024px) {
  .c-7,
  .c-5,
  .c-12 {
    grid-column: span 12;
  }
  .section-head,
  .split,
  .cta-inner {
    grid-template-columns: 1fr;
  }
  .sticky {
    position: static;
  }
}

@media (max-width: 860px) {
  .nav-links {
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    gap: 0;
    margin: 0;
    padding: 8px var(--gutter) 16px;
    background: var(--bg);
    border-bottom: 1px solid var(--line);
  }
  .nav-links.open {
    display: flex;
  }
  .nav-links a {
    padding: 12px 0;
    font-size: 17px;
    border-bottom: 1px solid var(--line);
    border-radius: 0;
  }
  .nav-links a:hover {
    background: transparent;
  }
  .nav-actions {
    margin-left: auto;
  }
  .menu-toggle {
    display: inline-grid;
  }
  .hero-inner {
    grid-template-columns: 1fr;
  }
  .hero-copy {
    padding-bottom: 0;
  }
  .hero-shots {
    min-height: 0;
  }
}

@media (max-width: 640px) {
  .nav-actions .btn {
    display: none;
  }
  .hero-meta {
    gap: 6px 20px;
  }
  .hero-shots .shot.front {
    width: 64vw;
    transform: translateX(-14%);
  }
  .hero-shots .shot.back {
    width: 50vw;
  }
  .quiz-options {
    grid-template-columns: 1fr;
  }
  .module summary {
    grid-template-columns: 30px minmax(0, 1fr) 14px;
  }
  .module .count {
    display: none;
  }
  .module ol {
    columns: 1;
    padding-left: 46px;
  }
  .path {
    grid-template-columns: 28px minmax(0, 1fr);
  }
  .path .meta {
    grid-column: 2;
    text-align: left;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-grid > :first-child {
    grid-column: span 2;
  }
}